The invention discloses a cemented soil and concrete composite pile and a construction method thereof. The construction method comprises the following steps: S1, performing setting out positioning according to a designed pile layout; S2, drilling; S3, inserting a spray pipe into a hole to the predetermined depth of the stratum; S4, performing jet grouting; S5, pulling out the pipe and washing to finish jet grouting pile construction; S6, performing cast-in-place concrete pile pore forming on the soil body above the top part of each jet grouting pile after the jet grouting pile construction is finished for 3-5 days; S7, digging the top part of each jet grouting pile to form a mortise; S8, filling plain concrete to the designed elevation of the top of each pile, vibrating and compacting to finish cemented soil and concrete composite pile construction. The composite pile body disclosed by the invention has the advantages that the connection is reliable, the integrality is strong, the vertical bearing capacity and the horizontal shearing resistance are higher, the pile body is not easy to damage under pressure, the adaptability to the stratum is strong, meanwhile, the construction is easy, the environmental pollution is small, the cost is low, and the like.